Timing-gear mounting



R. K. JACK v TIMING GEAR MOUNTING Filed Jan. 28, 1926 gwuenboz EFF/i7' LEK Gtrnnur.

Patented Oct. 5, 1926,

i UNITED STATES PATENT OFFICE.

ROBERT K. JACK, OF LANSNG, MCHIG if, ASSEGNOR TO GENERAL MOTORS CORPORA- TIMING-GEAR MOUNTNG.

Application filed January 28, 1926.

rhis invention aims to improve the mounting of the timing gears ct a gas engine'.

A further object is to take allthe detlecy tions and inaccuracies ot the cam shaft and the crank shaft in the bearings instead ot through the timing' gears, thereby freeing' the timing` gears from any possible da tion. Y

A still further object consists in mounting' a timing gear on a shaft bearing' and driving by means of dogs keyed to the end ot shaft and engagingthe gear.

One embodiment ot' the invention is shown in the accompanying drawing', wherein Fig; ure 1 is a vertical section through thel t'ront end of the crank case. Figure is a front elevation, showing' the timing gears and the driving' dogs.

Referring' to the drawing', numeral 1 is a crank case of an internal combustion engine` l/Vithin this crank case is the usual crank shaft 2 and cam shaft 3. The crank shaft is mounted in bearing' 4 in the front wall ot the crank case. Just outside this bearing' the crank shaft is reduced and entends through a bearing' member 5 secured by suitable fastening' means 6 to the `front wall oi the crank case. lotatably mounted on the outer tace of this bearing 5 is a timing` 7, this being' the smaller ot the two timing `gears. For the purpose ot driving' this timing gea-r, the crank shaft is extended beyond the bearingand keyed thereto as at 8 is the driving' dogl 9. The dog 9 has studs 10 projecting; inwardly therefrom and entering' recesscs 11 provided inthe face ot the gear 7. A suitable lock washer 12 and nut 13 maintain the dog in position on tie crank shai't.

Above the crank shaft and in axial alignment with the cam shat't 3 is a sleeve member 14. This sleeve member Vhas a centrally disposed flange 15 by which it is secured toV theV Serial No. 84,347.

case and serves as a bearing' for the crank shaft. Rctatably mounted on theouter end ot the sleeve .is the second timing Agear 17. secondtiming gear is of course the one of larger diameter and is of such size as to properly eng; ge timing' near 7. For-driving` th cam shaft trom this second timing lgear means is employed similar to that connecting the first timing; gear to the crank shaft. A. driving dog` 18 is secured in any convenient way to the end of the cam shaft and is held in position by a nut as at 19. The driving` dog is provided with studs 2O to engage suitable :fean es 21 in the tace ot 'the timing gear. c

The timing; gear may be covered as usual with front plate 99 through which the Acrank sha't't may be extended as at 23 and provided with a keyed pulley 24; tor operating' the titan belt.

The advantages resulting from this method or" mounting` the timing gears are seli'r evident. 'fhe inaccuracies and delle@ tions of the shafts are taken by the bearings and are not transferred to the gears. The clearance provided between the studs and the recesses inthe gears insures the free rot-ation at'all times of the gears on the sleevepon tions ot the bearings. A substantially noiseless timing' gear is thus provided and wear is reduced to the minimum.

T claim r sans tor driving cam. shaft from a crank shaft comp ising' a crank case?, the crank case having; a arine Ltor the crank shaft, a bearing;` in arial alignment there with secured to the. cr k case and through which hearing' the crank shaft pe rotatably mounted thereon, a d u keyed to the proie-cti l end otl the crank shaft and having3 rV f* in driving' emettereN ment with the gezin a cam shaft bearing;n and a gear thereon engaging; the. crank shaft gear and means for driving the cam shaft from its gear. Y

In testimony whereof I aiiix my signature.

K. JACK. 

